Battleground map: Wisconsin moves to tossup

With several new polls this week showing that the presidential race in Paul D. Ryan’s home state has tightened since Mitt Romney chose him as his running mate, The Times has updated its battleground map to show Wisconsin as a tossup.

The map allows users to test their own predictions of the electoral college outcome.

So far, none of the nine states listed as tossups has moved off the map, and with the political conventions about to open, polling likely will be too unstable to make any serious calls until after any temporary “bounces” dissipate. So for now, President Obama appears to be able to count on 237 electoral votes while Mitt Romney can count on 191, and 110 are up for grabs. A candidate needs a majority of the electoral votes – 270 – to win.

The Times map now has Michigan listed as leaning toward Obama. That’s consistent with most of the public polling in the state, including three recent polls showing the president with a 5- or 6-point lead. But at least one significant poll in July showed Romney with a 1-point advantage. If more such polls appear after the conventions, the state may move to tossup status.

On the other side of the ledger, repeated polls consistently have shown Obama leading in New Hampshire and Nevada. Unless the polling shifts after the conventions, those states may soon move to the “lean Obama” category.

Of the biggest battlegrounds, Romney may be establishing a small edge in Florida, where he has led in some recent polls. But Obama has shown a fairly consistent lead in Ohio, including two polls released Thursday. Ohio and Virginia, where Obama has led in most, but not all, recent polls, remain the most critical states. If Obama carries those two, it would be almost impossible to put together a realistic winning scenario for Romney.